Mechanism Research on the Swirling Air Flow Compounded with Magnetic-Field Finishing

2008 ◽  
Vol 53-54 ◽  
pp. 51-55 ◽  
Author(s):  
Xiu Hong Li ◽  
Shi Chun Yang
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Air Flow ◽  
Abrasive Particle ◽  
Solid Particles ◽  
Two Phase ◽  
Machining Time ◽  
Machined Surface ◽  
Magnetic Field Coupling ◽  
Swirling Air Flow

A new finishing technology of the swirling air flow compounded with magnetic-field is advanced. Force acting on abrasive is analyzed by the action of airstream and magnetic-field coupling according to gas-solid particles two-phase flow. Finishing mechanism on the swirling air flow compounded with magnetic-field is illustrated, namely, burrs and microcosmic peak on the surface of workpiece are broken, grinded and cut via a great deal of abrasive particle impacting, microchipping and rolling machined surface. Unthreaded hole is experimented on the condition of changing magnetic induction intensity B and machining time t. Changing curve of surface roughness Ra along with time t is shown. Research indicates that machining time of the swirling air flow compounded with magnetic-field is short and machining efficiency is high. The longer machining time is, the smaller surface roughness Ra is and the better machining effect is.

scholarly journals Annular Surface Micromachining of Titanium Tubes Using a Magnetorheological Polishing Technique

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 314 ◽  
Author(s):  
Wanli Song ◽  
Zhen Peng ◽  
Peifan Li ◽  
Pei Shi ◽  
Seung-Bok Choi
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Rotation Speed ◽  
Abrasive Particle ◽  
Internal Surface ◽  
Abrasive Particles ◽  
High Magnetic Field Strength ◽  
Titanium Alloy Tube

In this study, a novel magnetorheological (MR) polishing device under a compound magnetic field is designed to achieve microlevel polishing of the titanium tubes. The polishing process is realized by combining the rotation motion of the tube and the reciprocating linear motion of the polishing head. Two types of excitation equipment for generating an appropriate compound magnetic field are outlined. A series of experiments are conducted to systematically investigate the effect of compound magnetic field strength, rotation speed, and type and concentration of abrasive particles on the polishing performance delivered by the designed device. The experiments were carried out through controlling variables. Before and after the experiment, the surface roughness in the polished area of the workpiece is measured, and the influence of the independent variable on the polishing effect is judged by a changing rule of surface roughness so as to obtain a better parameter about compound magnetic field strength, concentration of abrasive particles, etc. It is shown from experimental results that diamond abrasive particles are appropriate for fine finishing the internal surface of the titanium-alloy tube. It is also identified that the polishing performance is excellent at high magnetic field strength, fast rotation speed, and high abrasive-particle concentration.

Vortex Simulation for Behavior of Solid Particles Falling in Air

2011 ◽  
Author(s):  
Hisanori Yagami ◽  
Tomomi Uchiyama
Keyword(s):  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Air Flow ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Vortex Method ◽  
Solid Particles ◽  
Particle Volume ◽  
Two Phase ◽  
Spherical Region

The behavior of small solid particles falling in an unbounded air is simulated. The particles, initially arranged within a spherical region in a quiescent air, are made to fall, and their fall induces the air flow around them, resulting in the gas-particle two-phase flow. The particle diameter and density are 1 mm and 7.7 kg/m3 respectively. A three-dimensional vortex method proposed by one of the authors is applied. The simulation demonstrates that the particles are accelerated by the induced downward air flow just after the commencement of their fall. It also highlights that the particles are whirled up by a vortex ring produced around the downward air flow after the acceleration. The effect of the particle volume fraction at the commencement of the fall is also explored.

Ultrasonic Polishing of Electric Discharge Machined Surface Using Al2O3 Suspension

2011 ◽  
Vol 291-294 ◽  
pp. 53-56
Author(s):  
Won Sik Lee ◽  
Jung Sik Seo ◽  
Se Hyun Ko ◽  
Jin Man Jang ◽  
Bermha Cha ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Wave ◽  
Electric Discharge ◽  
Complex Shape ◽  
Abrasive Particle ◽  
Particle Suspension ◽  
Machined Surface ◽  
3 Dimensional ◽  
Micro Parts ◽  
The Impact

The aim of this work is to investigate the possibility of improvement of surface roughness in the wire-EDMed sample by usinig ultrasonic wave and abrasive particle suspension. For this study, two-type ultrasonic polishing methods were used. Removal of the white layers on surface of EDMed sample depended largely on the movement of the suspended particles : the white layers are removed by the impact of free moving particles due to ultrasonic wave, so-called micro chipping mechanism. Even though the surface roughness was improved very slowly, 3-dimensional fine polishing was achieved in wire-EDMed micro PIM molds. These results indicated that micro polishing by ultrasonic wave using suspension is applicable to improvement of surface roughness of micro parts with 3-dimensional complex shape.

scholarly journals Pulsed Magnetic Field Treatment of TiAlSiN Coated Milling Tools For Improved Cutting Performances

2021 ◽  
Author(s):  
Hao Qu ◽  
Lin Zhang ◽  
Zhe Chen ◽  
Lei Zhang ◽  
Kyle Jiang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Cutting Force ◽  
Processing Parameters ◽  
Cutting Performance ◽  
Machining Process ◽  
Pulsed Magnetic Field ◽  
Machined Surface ◽  
Wear Area ◽  
Cutting Vibration

Abstract In this study a pulsed magnetic treatment was attempted to improve the cutting performance of the TiAlSiN coated WC-12wt%Co cemented carbide end mills and the effects of the strength of the pulsed magnetic field on the cutting forces, the cutting vibrations, the tool wear, the machined surface roughness and mechanical properties were investigated. It is found that the cutting performances of the coated tools are successfully improved with a relatively lower cutting force and less wear area. The average resultant cutting force Fxyave decrease by 14.53% in the last machining process when the optimum processing parameters of 0.5T magnetic field is used, accompanying a maximum decrease of 46.8% in the cutting vibration. The maximum reductions of 57.65% and 25.4% in the flank wear and the average surface roughness of the workpiece are obtained respectively after the treatment. Both the hardness and toughness of the cemented carbides are slightly improved with the imposition of the field. The improvements in the cutting performance of the tool are attributed to the enhanced adhesion strength between the coating and matrix, which is caused by the increased compressive residual stress induced by the PMT.

Optimization Method of Rotational Axis Motion in 5-Axis Controlled Machining to Keep Command Tool Feed Rate

2020 ◽  
Author(s):  
Takayuki Nakamura ◽  
Kohei Ichikawa ◽  
Masanobu Hasegawa ◽  
Jun'ichi Kaneko ◽  
Takeyuki Abe
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Machining Process ◽  
Rotational Axis ◽  
Feed Speed ◽  
Machining Processes ◽  
Machining Time ◽  
Machined Surface ◽  
Lead Angle ◽  
Tool Posture

Abstract In recent machining processes, 5-axis controlled machine tool is widely used for machining complicated workpiece shape with curved surface. In such process, to achieve high productivity, planning method of cutting conditions to satisfy both following the commanded tool feed rate in machining process and realization of good surface roughness are required. In conventional study, it is known that lead angle of tool posture against local machined surface influence the surface roughness. Then, common commercial CAM systems have already functioned to avoid interference and control the lead angle in each cutter location. However, in the generated cutter locations by the conventional algorithms, when the tool posture changes rapidly, there is a problem that actual feed rate does not reach the command value and machining time becomes longer than expected. In this paper, we propose the new tool posture correction algorithm. In the proposed method, first, the rotational axis that causes the feed speed rate decline is specified by preliminary experiments. And, the jerk value that is the threshold for the feed speed decline is investigated. After that, for the NC program, the command value of the target axis is modified within a range where interference of cutting tool does not occur, thereby preventing a decline in the actual feed rate. This paper describes an outline of the proposed modification method and the effect of the modification of the target axis positions on the lead angle and the actual feed rate.

Analysis of Forces During Spot Finishing of Titanium Alloy Using Novel Tool in Magnetic Field Assisted Finishing Process

2018 ◽  
Author(s):  
Anwesa Barman ◽  
Manas Das
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Normal Force ◽  
Tangential Force ◽  
Abrasive Particle ◽  
Initial Surface ◽  
Precise Control ◽  
Percentage Improvement ◽  
Finishing Process

Magnetic field assisted finishing process is a nanofinishing process which uses magnetic field for precise control of finishing forces. Magnetorheological fluid mixed with diamond abrasive particles in base medium of glycerol, hydrofluoric acid, nitric acid, and deionized water is used as the polishing medium. The novel tool is a magnet fixture made of mu-metal which is used to hold the magnet during finishing. In the present experimental study, finishing at a spot on flat titanium alloy is carried out to analyze the forces involved in the finishing. Normal force is the main force responsible for the indentation by the abrasive particle on the workpiece surface. Tangential force helps in removing indented material. The measured normal force and tangential force during the spot finishing are 3.285 N and 0.43 N, respectively. The final surface roughness achieved after spot finishing is 10 nm from initial surface roughness of 200 nm. The percentage improvement in surface roughness is 95%.

Experimental Characterization of Particle-Laden Air Flow Across Horizontal Pipe Junctions

2018 ◽  
Author(s):  
Tariq S. Khan ◽  
Mohamed Alshehhi ◽  
Xu Rumin ◽  
Saqib Salam
Keyword(s):  
Mass Fraction ◽  
Solid Phase ◽  
Flow Behavior ◽  
Air Flow ◽  
Industrial Applications ◽  
Solid Particles ◽  
Gas Flows ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Particle Sizer

There are several industrial applications in which two phase solid-gas flows are involved. At times, pipe junctions are involved where flow split takes place. Present study consists of experimental investigation of turbulent gas-solid two-phase flow through horizontal pipe junctions. The effects of air flow rate, branch diameter and pipe orientation at junctions are investigated on mass fraction, phase split and solid particles distribution across the junctions. Silica powder, in the monodispersed size of 15 μm was injected into the pipelines by a micro-feeder. The powder was entrained in an air flow which passed horizontally through a long straight channel of circular pipe with T and Y junctions. The main pipe was 51mm in diameter while the inlet superficial velocity of gas was varied from 5 m/s to 13.5m/s. The particles mass concentration was measured by the aerodynamic particle sizer (APS). Experimental results showed that solid phase split followed air flow split while decreasing the inlet air velocity caused major decrease in the mass fraction at junction pipe. The orientation of junction pipe has a significant effect on the flow behavior along the pipe. These results indicate that the behavior of solid particles is a complex phenomenon in pipe flows.

LDV measurements of an air–-solid two-phase flow in a horizontal pipe

1982 ◽  
Vol 120 ◽  
pp. 385-409 ◽  
Author(s):  
Yutaka Tsuji ◽  
Yoshinobu Morikawa
Keyword(s):  
Two Phase Flow ◽  
Air Flow ◽  
Solid Particles ◽  
Laser Doppler Velocimeter ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Frequency Spectra ◽  
Loading Ratio ◽  
Flow Turbulence

Measurements of air and solid velocities were made in an air-solid two-phase flow in a horizontal pipe by the use of a laser-Doppler velocimeter (LDV). The pipe was 30 mm inner diameter, and two kinds of plastic particles, 0.2 and 3.4 mm in diameter, were conveyed in addition to fine particles (ammonium chloride) for air-flow detection. The air velocities averaged over the pipe cross section ranged from 6 to 20m/s and the solid-to-air mass-flow ratio was up to 6. Simultaneous measurements of both air and 0.2 mm particle velocities were found possible by setting threshold values against the pedestal and Doppler components of the photomultiplier signal.As the loading ratio increased and the air velocity decreased, mean-velocity distributions of both phases increased asymmetrical tendency. I n the presence of 0.2mm particles, a flattening of the velocity profile was remarkable. The effects of the solid particles on air-flow turbulence varied greatly with particle size. That is, 3.4 mm particles increased the turbulence markedly, while 0-2 mm ones reduced it. The probability-density function of the air flow deviated from the normal distribution (Gaussian) in the presence of particles. Finally, the frequency spectra of air-flow turbulence were obtained in the presence of 0.2 mm particles by using a fast Fourier transform (FFT). As a result, it was found that t,he higher-frequency components increased with increasing loading ratio.

scholarly journals Effect of abrasive particle morphology along with other influencing parameters in magnetic abrasive finishing process

2021 ◽  
Vol 22 ◽  
pp. 15
Author(s):  
Farshid Ahmadi ◽  
Hassan Beiramlou ◽  
Pouria Yazdi
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Abrasive Particle ◽  
Particle Morphology ◽  
Orthopedic Implants ◽  
Spherical Particles ◽  
Machining Time ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Particles ◽  
Abrasive Finishing

Surface characteristics play a very important role in medical implants and among surface features, surface roughness is very effective in some medical applications. Among the various methods used to improve surface roughness, magnetic abrasive finishing (MAF) process has been widely used in medical engineering. In this study, the effect of abrasive particle morphology along with four other process parameters, including type of work metal, finishing time, speed of finishing operation, and the type of abrasive powder were experimentally evaluated. Full factorial technique was used for design of experiment. Three commonly used metals in orthopedic implants i.e., Ti-6Al-4V alloy, AZ31 alloy and austenitic stainless-steel 316LVM, were selected for this study. Also, two types of magnetic abrasive particles with different shapes (spherical and rod-shaped) were considered in the experiments. The results of the experiments indicated that the morphology of the abrasive particles and the finishing time had the greatest effect on surface roughness and using rod-shaped abrasive particles resulted in better surface quality comparing to the spherical particles. Besides, the surface quality of steel 316LVM after MAF was the best among the other examined metals. Interaction plots of ANOVA also showed that interactions of material with morphology of abrasive particles, and material with machining time were found to be reasonably significant.

Erosion of Metallic Plate by Solid Particles Entrained in a Liquid Jet

1983 ◽  
Vol 105 (3) ◽  
pp. 215-222 ◽  
Author(s):  
M. T. Benchaita ◽  
P. Griffith ◽  
E. Rabinowicz
Keyword(s):  
Analytical Approach ◽  
Theoretical Study ◽  
Abrasive Particle ◽  
Solid Particles ◽  
Silica Sand ◽  
Liquid Jet ◽  
Phase Flow ◽  
Industrial Equipment ◽  
Metallic Plate ◽  
Two Phase

An experimental and theoretical study on erosion of a metallic plate by solid particles entrained in a liquid jet has been performed. The test section involved a two-phase flow jet of liquid water and silica-sand impinging on a metallic plate upon which erosion occurred. In combining the fluid mechanics of particle suspension in a liquid and a model of weight removal from the plate (by a single abrasive particle), an analytical approach is developed to determine the distribution and amount of erosion along a metallic plate. This model of erosion distribution along the metallic plate can be used as a tool to predict erosive damage in industrial equipment such as pipe bends, elbows, subsurface safety valves, and pipe contractions.

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